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Updated: Feb 15, 2026
Contractility Measurements on Isolated Papillary Muscles for the Investigation of Cardiac Inotropy in Mice
Published on: September 17, 2015
Cardiac mesothelial papillary hyperplasia in four dogs
Shannon G Kirejczyk1,2, Anne L Burnum1,2, Corrie C Brown1,2
1Department of Pathology (Kirejczyk, Burnum, Brown, Sakamoto, Rissi), College of Veterinary Medicine, University of Georgia, Athens, GA.
Abstract:
Mesothelial papillary hyperplasia (MPH) has been described as an incidental finding on the epicardial surface of clinically normal laboratory Beagle dogs. We describe MPH in 4 dogs diagnosed with acute cardiac tamponade (1 case) or chronic cardiac disease (3 cases). Cardiac MPH appeared as distinct, soft, irregular villous plaques on the epicardial surface of the auricles and occasionally the ventricles. Histologically, areas of MPH were composed of multiple papillary fronds arising from the epicardial surface and projecting into the pericardial space. Fronds were covered by cuboidal and occasionally vacuolated mesothelial cells and were supported by loose fibrovascular stroma with various degrees of edema and inflammation. Although these may represent incidental findings with no clinical significance, the gross appearance warrants differentiation from other conditions. Additional insight into the pathogenesis of MPH is needed to fully understand its significance in the face of concurrent cardiac disease.
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